How a freshman Republican senator became one of Donald Trump’s most outspoken critics in Washington

Reporting from Washington  — Nebraska’s new senator spent his first year as fresh arrivals to Capitol Hill are supposed to: head down, hard at work, zero speeches.

No more.

The rise of Donald Trump to GOP presidential nomination turned the senator, Republican Ben Sasse, into one of Trump’s most outspoken opponents in Congress, and Sasse’s pronouncement that he will not back Trump ahead of Tuesday’s Nebraska primary brought him an onslaught of attention. But he’s been at it since long before House Speaker Paul D. Ryan and others piled on against Trump last week.

For months, Sasse has sketched out his philosophical underpinnings late at night on social media, and he is seriously floating the need for a third option in the presidential race.

Though many would like Sasse, the former president of a small Lutheran liberal arts college, to lead such a ticket, he prefers instead to sit by the Platte River late into the night after his kids are asleep and tweet questions and comments to, and about, Trump.

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“Ignored my phone most of today. Voicemail is now overflowing with GOP politicos telling me ‘Sure, Trump is terrible, but …’” he wrote after Trump all but clinched the GOP nomination last week. “But we ‘have to’ support him,’ because the only choice is Trump or Hillary.’ ummm, WHY? #Neither.”

Sasse released an open letter on Facebook last week — a follow-up to one he wrote in February — sketching out why he would be supporting neither Trump nor Democratic front-runner Hillary Clinton.

“This letter is for the majority of Americans who wonder why the nation that put a man on the moon can’t find a healthy leader who can take us forward together,” he wrote. “Our founders didn’t want entrenched political parties. So why should we accept this terrible choice?”

The senator’s musings are being met with mixed response. Trump is expected to do well in the state — Republican Gov. Pete Ricketts is on board, as are other GOP leaders. Attacking the front-runner has exposed Sasse, who had never held public office until becoming a senator in 2015, to criticism.

“Before the Never Trump part, he was a rock star,” said Jon Tucker, chairman of the Republican Party in Douglas County, where Omaha is located.

Tucker said Republicans in Nebraska still like Sasse, but he had an eye-opening moment while passing the hat for $1 donations during debate watch parties and voters wouldn’t give to the GOP because of what Sasse was up to.

“I don’t see people with draft Sasse T-shirts walking around Nebraska,” he said.

But Mark Fahleson, who nudged Sasse to run for Senate and recently took in an Alan Jackson concert with Sasse and both their families, sees in his friend a thoughtful politician who is just trying to the influence the debate.

“Do I think he will run for president this cycle? No,” Fahleson said. “My guess is he’s not done this cycle speaking out.”

At 44, the Harvard- and Yale-educated Sasse has had a robust and varied career — working initially as a corporate turnaround specialist, but eventually returning to academia and then pursuing government jobs in President George W. Bush’s administration. He also worked briefly as the chief of staff to a Nebraska congressman, and was a tutor and proctor for the House page program.

More recently, he was the president of Midland College in his hometown of Fremont, when he launched a 16-month bus tour to win the Republican nomination to replace a retiring senator.

Some say Sasse has talked about running for president since he was young, and they view his third-party musings as simply political positioning for an inevitable candidacy.

But those familiar with the senator’s thinking dismissed that as inaccurate. His office said he has zero interest, at the moment, in the White House. The very conservative father of young home-schooled children, he is focused on his family and job, his aides said.

“The answer is no. Sen. Sasse has been clear when asked this before: He has three little kids and the only callings he wants — raising them and serving Nebraskans,” a spokesman said. The senator declined a request for an interview.

In many ways, those who have watched Sasse’s short congressional career see an arc. Rather than becoming the next rabble-rouser, as headlines predicted, in the mode of Texas Sen. Ted Cruz, he instead used his maiden speech late last year to urge his peers to do the “hard work” of debating issues beyond partisan soundbites. He became a spokesman for a more elevated civic discourse.

“Conservatives will need to find a third option,” he wrote back in February. “Mr. Trump’s relentless focus is on dividing Americans, and on tearing down rather than building back up this glorious nation.”

Days before the Iowa caucuses on Feb. 1, Sasse stayed up late one night trolling Trump with personal and policy questions on Twitter. In one, he said Trump brags about affairs with married women and asked whether he repented or whether he thinks it matters.

Trump responded a few days later that Sasse looked “like a gym rat.”

“How the hell did he ever get elected?” Trump asked.

Sasse’s Facebook posting last week, though, caught more widespread attention

“Most Americans can still be for limited government again — if they were given a winsome candidate who wanted Washington to focus on a small number of really important, urgent things — in a way that tried to bring people together instead of driving us apart,” he wrote.

“I think there is room — an appetite — for such a candidate.”

Washington perked up, envisioning Sasse as a white-knight savior for a GOP in turmoil. Breathless commentary ensued; conservative writer William Kristol tweeted over the weekend about his outreach to Sasse as well as to former nominee Mitt Romney.

Back home, though, talk of a President Sasse was met with a pragmatic Midwestern shrug.

“He’s very much his own person, and I think Nebraskans respect that,” said Phil Young, a former executive director of the Nebraska GOP. “It just kind of depends on how far he wants to take this.”

lisa.mascaro@latimes.com

Follow on Twitter @LisaMascaro

UPDATES:

8:15 p.m.: This story was updated with background on Sasse’s first speech from the Senate floor.

This story was originally published at 12:39 p.m.